Injectable Graphene Oxide/Hydrogel-Based Angiogenic Gene Delivery System for Vasculogenesis and Cardiac Repair

Abstract

The objective of this study was to develop an injectable and biocompatible hydrogel which can efficiently deliver a nanocomplex of graphene oxide (GO) and vascular endothelial growth factor-165 (VEGF) pro-angiogenic gene for myocardial therapy. For the study, an efficient nonviral gene delivery system using polyethylenimine (PEI) functionalized GO nanosheets (fGO) complexed with DNAVEGF was formulated and incorporated in the low-modulus methacrylated gelatin (GelMA) hydrogel to promote controlled and localized gene therapy. It was hypothesized that the fGOVEGF/GelMA nanocomposite hydrogels can efficiently transfect myocardial tissues and induce favorable therapeutic effects without invoking cytotoxic effects. To evaluate this hypothesis, a rat model with acute myocardial infarction was used, and the therapeutic hydrogels were injected intramyocardially in the peri-infarct regions. The secreted VEGF from in vitro transfected cardiomyocytes demonstrated profound mitotic activities on endothelial cells. A significant increase in myocardial capillary density at the injected peri-infarct region and reduction in scar area were noted in the infarcted hearts with fGOVEGF/GelMA treatment compared to infarcted hearts treated with untreated sham, GelMA and DNAVEGF/GelMA groups. Furthermore, the fGOVEGF/GelMA group showed significantly higher (p < 0.05, n = 7) cardiac performance in echocardiography compared to other groups, 14 days postinjection. In addition, no significant differences were noticed between GO/GelMA and non-GO groups in the serum cytokine levels and quantitative PCR based inflammatory microRNA (miRNA) marker expressions at the injected sites. Collectively, the current findings suggest the feasibility of a combined hydrogel-based gene therapy system for ischemic heart diseases using nonviral hybrid complex of fGO and DNA.

Graphene materials as 2D non-viral gene transfer vector platforms

“…In addition, the positive charges of PEI facilitate the release of the cargo from the endosome thanks to the "proton sponge" effect. The most common approach consists of the covalent engraftment of polyethylanimine (PEI) via EDC/ NHS chemistry onto both GO and reduced GO (rGO) flakes 34,[37][38][39][40][41][42][43][44][45][46][47] . Noncovalent but electrostatic interactions have also been used to anchor PEI onto graphene nanoribbons (GNR) 48 , GO 49 and rGO/Au composites 50 .…”

“…Only two recent reports have attempted to express genes with either therapeutic purposes or aiming to unchain a change in cell fate. Paul and colleagues designed a hydrogel formulation able to release PEI-GO/pDNA complexes, where the cassette encoded the vascular endothelial growth factor (VEGF) gene 40 .…”

“…Remarkably, only four out of the twenty-seven studies using GBMs to deliver a genetic payload published so far have provided data on in vivo models 40,45,57,62 , one of them limited to the injection of the material at the one-cell stage of zebrafish embryos. Therefore, one of the main challenges ahead in order to validate these materials as gene delivery vectors is to confirm whether their encouraging in vitro performance stands in the in vivo setup.…”

One-Step Synthesis of Graphene Oxide–Polyamidoamine Dendrimer Nanocomposite Hydrogels by Self-Assembly

“…4,5 Biopolymer surface-functionalized GO nanosheets were reported to be biocompatible and non-toxic at low concentrations. 6,7 GO has recently been applied to prepare polymer nanocomposite hydrogels with improved mechanical performance compared to conventional hydrogels, 8,9 and various self-assembly approaches were used to prepare physically cross-linked GO-polymer nanocomposite hydrogels. 10,11 The driving forces to form these hydrogels were physical interactions including π-π interaction, hydrogen bonding, electrostatic interaction and coordination.…”

Nano-Engineered Biomaterials for Tissue Regeneration: What Has Been Achieved So Far?

“…Graphene oxide (GO) sheets are an alternative carbon-based nanomaterial, which have shown biocompatibility with no acute toxic effects in vivo (Paul et al, 2014;Park et al, 2015b). GO sheets and flakes with a thickness on the nanometer scale and length in the area of 1-6 μm are not taken up by cells but can absorb ECM proteins from culture serum .…”